Shot hole protective device



' Feb. 3, 1959 A. J. HllNrzE ETAL sHo'r Hom-zv PROTECTIVE DEVICE 2 Sheets-Sheet 1 Filed Sept. 4, 1953 37 fffffi 'if' INVENTORS A. JH

Feb. 3, 1959 A. J. HINTzE ErAL 2,371,785

SHOT HOLE PROTECTIVE DEVICE 2 Sheets-Sheet 2 Filed Sept. 4. 1953 A TTO/VEYS SHOT HLE PROTECTIVE DEVICE Alma'l. Hintze and'lviurrel C. Klaus, Bartlesville, Okla.,

-assignors to Phillips Petroleum Company, a corporation of Delaware Application September 4, 1953, Serial No. 378,548

4 claims. (el. 1oz-2z) This invention relates to deiiectors for shot holes. In another aspect 1t relates to a shot hole casing anchor for use in seismic surveying.

In geophysical prospecting by means of seismic sur- Veys 1t 1s common to produce vibrations in the regions of interest by means of explosive charges. For the most part these explosive charges are positioned a substantial distance beneath the lsurface of the earth in suitable shot holes which are drilled in'any well known manners such as by cable tool or rotary drills. The explosive charge is positioned at the bottom of such a shot hole and is tampedby filling the hole with water. The charge then is detonated electrically by conductors which extend from the bottom of the shot hole to a detonator positioned at the surface. When the explosion is created, and particularly when charges of considerable size are employed, the tamping water and quantities of mud, rock particles and the like are violently ejected from the hole and can cause considerable damage to nearby property. One particular danger results from the possibility of the detonation conductors being blown against power lines. This can cause disruption of service and possible electrocution of the seismic operating crew.

In the deeper shot holes it is customary to insert casing I into the hole to prevent cave-ins s o that additio-nal shots can be tired from the hole if desired. With the use of large explosive charges there is some danger of the casing actually being ejected from the shot hole. This, of course, results in considerable danger to nearby property and to the operating crew.

It, therefore, is important to provide some type of deflecting mechanism at the surface of the shot hole to direct the debris blown from the shot hole in a direction such that no damage is caused to nearby property. It also is important to provide some means for anchoring the casing in shot holes whenever large explosive charges Vare employed. The present invention is directed primarily toward providing such protective devices.

Accordingly, it is an object of this invention to provide an improved detlector for use over shot holes.

Another object is to provide an improved shot hole deflector of rugged construction, simplified design, adjustable, and which can be used with either cased or uncased holes.

A further object is to provide an anchor device to retain the casing in shot holes.

A further object is to provide a combined deflector and casing anchor for use with shot holes in seismic prospecting.

The apparatus of this invention comprises, generally, a hood member which is adapted to be fitted over the top of a shot hole. The upper portion of the hood is curved and the hood is adjustably mounted such that debris projected -through the hood can be directed toward any desired location. This hood conveniently is mounted on the back of a water truck or the like. This makes the device portable and at the same time provides anchor or ballast means to retain the hood in position 'ilj Patented Feb. 3, 1959 against the force of the explosive charge. A cap having a central opening therein also is provided to lit over the top of the casing in a cased shot hole. A supporting frame is attached to the cap and extends outwardly therefrom to engage the under side of the hood whenever there is a force exerted on the casing which tends to expel it from the shot hole. The hood thus functions to anchor the casing in the shot hole.

Various other objects, advantages and features of this invention should become apparent from the following detailed description taken in conjunction with the accompanying drawing in which:

Figure 1 illustrates the shot hole protecting mechanism of this invention in operative position over the top of a shot hole;

Figure 2 is a top view of a portion of the shot hole deflector;

Figure 3 is a side view, shown partially in section, of the deflector and casing anchor member;`

Figure 4 is a sectional view taken along line 4 4 in Figure 1;

Figure 5 is a top view of the casing anchor member; and

Figure 6 is a sectional view taken along line 6-6 in Figure 5.

Referring now to the drawing in detail and to Figure l in particular there is shown a shot hole 10 in the earth 11, shot hole 10 being fitted with a casing 12. At the bottom of shot hole 1li there is positioned an explosive charge 13 which is electrically connected to a detonator 14 at the surface of the earth by a pair of connecting leads 15 and 16. The deflector 17 of the present invention is shown in operative position above shot hole 10. This deector comprises a frusto-conical hood 1S which is mounted axially with shot hole 10. An upright conduit 19 is Welded tothe top of hood 18 and a 45 elbow 20 is welded to the top of conduit 19. A barrel 21 is, in turn, lwelded to the top of elbow 20. The upper end of the barrel is provided with one or more depending prongs 22 which are provided to engage detonator connecting leads 1S and 16 following the explosion. This prevents the leads from being projected beyond barrel 21. Prongs 2.2 are illustrated in greater detail in Figure 4. e

The deflector 17 is shown as being mounted on the back of a water truck 25. This mounting comprises gen-V erally a pair of bars 26 and 27, see Figures 1 and 2, which are attached to the bed of truck 25 and extend rearwardly therefrom. A pair of transverse bars 28 and 29 are attached across bars 26 and 27 and a pair of bars 31 and 32 are connected between bars 28 and 29. Bars 28, 29, 31 and 32 thus form a square frame which encloses upright conduit 19. A first annular plate 33 is welded to conduit 19 and rests upon the frame formed by bars 28, 29, 31 and 32. A second annular plate 34 is likewise welded to conduit 19 at approximately its junction with hood 1S, plate 34 being in engagement with the lower surface of the frame formed by bars 28, 29, 31 and 32. In this manner the entire deector is free to rotate about the common axis of hood 18, conduit 19 and shot hole 10. To facilitate this rotation a plurality of short sections of pipe 36 are welded to the top surface of annular plate 33. A plate 37 having an opening therein is attached to bar 29 and a rod 38 is provided to lit through one of the rods 36 and plate 37 to lock the deflector in a predetermined position. Rod 38 has a curved end to prevent its being disengaged accidentally. By rotating this curved end to an upright position, rod 38 can be removed from plate 37 and used as a lever to turn deector 17 to any desired position. In Figure 2 there is shown a second possible position of the deector wherein barrel 21 is pointed at right angles to the direction that truck 25 is facing.

It should of course be apparent that rods 36 can be provided on plate 33 at any desired angle with respect to barrel 21. Furthermore, it should be apparent that the deflector can be constructed such that barrel 21 maires any desired angle with the vertical axis of conduit 19. For example, barrel 21 can be pointed in a horizontal direction or even downwardly. While the deflector has Ibeen illustrated as being mounted on a water truck, this particular mounting is by no means essential to satisfactory operation of the deector. The Water truck provides a convenient mounting because such a truck generally is available when a rotary drilling rig is employed to drill the slot hole, and such a truck provides suiicient weight to anchor the hood against the explosive force from the shot hole. It further should be apparent that the particular illustrated framework used to attach deiiector 17 to truck 25 merely represents one possible configuration and various other types of connecting mechanism obviously can be employed if desired.

ln addition to the deiiecting hood, there is provided in accordance with this invention a frame member 4) which operates as an anchor to retain casing 12 within shot hole 1@ when large explosive charges 13 are eniployed. With reference to Figures 5 and 6 in particular, this frame member is shown as comprising an annular cap 41 having a central opening l2 in the top thereof. Cap 41 is provided with a lip 43 which fits over the top of casing 12. A pair of annular members 45 and 46 are welded to cap 41 on opposite sides thereof. Members 45 and 46 and cap 41 are threaded to receive set screws 47 and 48 which engage casing 12. Since the casings employed in the various shot holes are not exactly uniform in outer diameter, set screws 47 and 48 are used to establish a tight engagement of cap 41 with casing 12. Annular protecting caps 50 and 51 are welded to cap 41 and enclose respective members 45 and 46. These caps extend outwardly beyond the set screws to protect the ends thereof.

Cap 41 is attached to a supporting frame which ex-V tends outwardly therefrom to engage the lower surface of hood 18 whenever casing 12 tends to be displaced upwardly. This frame member comprises a pair of horizontal rods 53 and 54 which are of slightly greater length than the diameter of the lower edge of hood 18. Flat plates 55 and 56 are welded to the top surfaces of the ends of rods 53 and 54 to provide surfaces to engage the lower edge of hood 18. Flat plates 57 and 58 are mounted perpendicular to respective plates 55 and 56 and extend downwardly across the ends of rods 53 and 54. A second pair of rods 59 and 66 are joined to one another and extend between plates 57 and 58. These rods 59 and 60 lie in a common vertical plane with rod 53, and a flat metal plate 62 is interposed between rod 53 and rods 59 and 60. Plate 62 is provided with a central opening which lits about cap S1. A third rod structure corresponding to the second pair of rods is provided in the vertical plane with rod 54. This structure includes a connecting plate 64, a rod 66, and an additional rod, not shown, which corresponds to rod 59. Plate 6d is provided with an opening which is iitted about cap Sti.

The anchor member 40 can thus be placed over the top of a cased well and attached to the casing by set screws 47 and 48. Hood 18 then is positioned over the anchor member such that if casing 12 tends to be expelled from the shot hole, plates 55 and 56 engage the lower edge of hood 1S and are held down thereby. However, it should be apparent that the details of assembly of the anchor member are merely illustrative of a preferred embodiment thereof and are not intended to limit the invention.

From the foregoing description it can be seen that there is provided in accordance with this invention a protective assembly for use over shot holes in seismic surveying. One important feature of this invention is that the deflecting hood is portable and can be employed equally well in conjunction with a cased or uncased well. If desired, the hood can be detached from the truck and placed directly over the hood, the weight of the hood holding it in place. The casing anchor device becomes valuable for use in conjunction with cased wells wherein rather large explosive charges are detonated. While the invention has been described in conjunction with a present preferred embodiment thereof, it should be apparent that the invention is not limited thereto.

What is claimed is:

l. A detiector for use over shot holes comprising, in combination, a frusto-conical hood member adapted to be positioned over a shot hole, an upright conduit attached to the upper end of said hood member, a second conduit attached to the upper end of said upright conduit and extending therefrom at a predetermined angle with the axis of the shot hole to direct debris projected from the shot hole in a predetermined direction, at least one prong attached to the inner Wall of said second conduit and extending therefrom into the interior of said second conduit, a frame enclosing said upright conduit, a first plate secured to said upright conduit and resting on the top of said frame to permit rotation of said upright conduit in said frame, a second plate attached to said upright conduit and engaging the bottom of said frame, and means attached to said frame to secure said hood to a ballast member to retain said hood member in position over the shot hole against the force of debris being projected from the shot hole.

2. The combination in accordance with claim 1 further comprising a plurality of hollow conduits mounted on said iirst plate, a bar inserted in one of said hollow conduits, and means to retain said bar in a predetermined position when inserted in one of said conduits.

3. A deector for use over shot holes comprising, in combination, a frusto-conical hood member adapted to be positioned over a shot hole, an upright conduit attached to the upper end of said hood member, a second conduit attached to the upper end of said upright conduit and extending upwardly therefrom at an angle of approximately 45 with the axis of the shot hole to direct debris projected from the shot hole in a predetermined direction, a plurality of prongs attached to the inner wall of said second conduit and extending therefrom into the interior of said conduit, a frame enclosing said upright conduit, a first annular plate secured to said upright conduit and resting on the top of said frame to permit rotation of said upright conduit 1n said frame, a second annular plate attached to said upright conduit and engaging the bottom of said frame, and means attached to said frame to secure said hood to a ballast member to retain said hood member in position over the shot hole against the force of debris being projected from the shot hole.

4. A deflector for use over shot holes comprising, in combination, a frusto-conical hood member positioned over a shot hole, an upright conduit attached to the upper end of said hood member, a second conduit attached to the upper end of said upright conduit and extending therefrom at a predetermined angle with the axis of the shot hole to `direct debris projected from the shot hole in a predetermined direction, a plurality of prongs attached to the inner wall of said second conduit and extending therefrom into the interior of said conduit, a frame enclosing said upright conduit, a iirst annular plate secured to said upright conduit and resting on the top of said frame to permit rotation of said upright conduit in said frame, a second annular plate attached to said upright conduit and engaging the bottom of said frame, means attached to said frame to secure said hood to a ballast member to retain said hood member References Cited in the file of this patent UNITED STATES PATENTS Rogers et al. Oct. 30, 1945 Williams June 14, 1949 

